1. Field of the Invention
This invention relates to an improved process for the preparation of hydrocarbon oxidation catalyst compositions. More particularly, it relates to a new vanadium (IV) phosphate having a substantially improved intrinsic surface area and to a novel method for its production. Still more particularly, it relates to the production of maleic anhydride from n-butane in a vapor phase process employing the foregoing phosphate catalyst.
2. Prior Art Description
The preparation of mixed oxide compositions of vanadium and phosphorus and the use of these compositions as catalysts in hydrocarbon oxidations is known in the art. The conventional preparative methods are unsatisfactory in that:
(1) they usually require that the process equipment be fabricated of special corrosion-resistant materials of construction; and
(2) they are troubled by serious waste disposal problems. These difficulties arise from the employment of hydrogen chloride or oxalic acid for the dissolution of the vanadium component.
The known mixed oxide compositions, in general, suffer from a number of disadvantages which include relatively poor selectivities and activities as catalysts in the partial oxidation of a saturated hydrocarbon feed, for example n-butane to maleic anhydride, and the like oxidations with molecular oxygen.
Representative descriptions in the art which relate to the production of maleic anhydride from n-butane include U.S. Pat. No. 3,293,268.